Crashes that result from vehicles driving through red lights are often very serious because they are typically right-angle or side-impact crashes. While newer vehicles have many standard safety features such as lane departure warning and brake assistance systems to support drivers, they do not have technologies to help prevent driving through red lights. This project developed an algorithm that integrated traffic light phasing information with GPS data to warn drivers when they were approaching a red light, providing valuable driver assistance and improving traffic safety and efficiency.
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Comparing the Effectiveness of No Right Turn on Red Sign Types at Traffic Signals
Preventing right turns on red at traffic signals is a generally effective pedestrian safety measure. But when pedestrians are absent, allowing right turns on red can improve traffic flow. Unlike static signs that prohibit right turns on red, dynamic No Right Turn on Red (NRTOR) signs can be activated when pedestrians are present. Comparing driver compliance with dynamic and static signs indicated that each sign type may have its own benefits.
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Assessing Reliability and Resilience on Freeway Corridors
Drivers and businesses benefit from a freeway network that is predictable and able to withstand disturbances such as construction, incidents and poor weather. To provide a high level of service on freeways, traffic managers monitor and assess traffic flows and speeds under various conditions. In this project, investigators analyzed and identified the most vulnerable portions of the Twin Cities freeway network and enhanced an analysis tool to provide better estimates of travel-time reliability and operational resilience.
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Repairing In-Water Bridge Supports Using Innovative Methods and Materials
In recent years, advancements in bridge repair techniques and technologies promise to offer more options for strengthening an existing bridge’s in-water piles, eliminating the need to reroute both water and traffic. This project investigated other states’ experiences with several products on the market and provided an opportunity for Minnesota’s engineers to evaluate two vendors’ systems on a bridge in need of restoration.
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Examining Driver Preferences for Lane Line Patterns and Widths
Pavement markings that clearly delineate lanes are important for reducing crashes and improving the safety of drivers. The configurations of these pavement markings—primarily the width and length of the line and the spacing of broken lines—vary from state to state. This project identified driver preferences for pavement marking patterns and widths, which can increase visibility and improve safety.
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Examining off-peak transit behaviors to improve transit equity
Originally published in Catalyst, February 19, 2025
Transit service planning has traditionally focused on peak trips and the needs of “rush hour” commuters rather than off-peak travel. Often, off-peak trips are taken by shift-based essential workers and those who cannot or do not drive. The COVID-19 pandemic further underscored the need for a closer examination of these trips to improve social equity.
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Understanding the Performance of Road Base Stabilization Additives
Full-depth reclamation (FDR)—an effective and efficient pavement reconstruction method—can be made even more sustainable by strengthening the road base. Laboratory and field testing of proprietary stabilizers used to amend FDR material illustrated improvements in pavement stiffness and economic benefits over time. New pavement design standards for base stabilizers can guide road engineers in choosing the optimal products for sustainable roads.
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New Clear Roads Research: Dashboards for Improving Winter Operations
From Clear Roads, March 5, 2025
Transportation agencies collect vast amounts of data about their winter operations. Dashboards can help to summarize the information, measure performance, inform decision-making during winter weather events and improve planning for future storms.
This Clear Roads project examined the use of dashboards among transportation agencies to assess current strategies and identify innovative and effective practices. The results offer guidance to transportation agencies that are considering implementing or expanding their dashboard use to enhance winter maintenance operations.
Download the final report and two-page brief: CR 22-05 – Use of Dashboards for Winter Operations, December 2024.
New Project: Roundabouts, J-Turns, etc. – Understanding Their Economic Impacts
Roundabouts and J-turns have consistently shown significant improvements in safety and traffic flow in Minnesota and across the U.S. Still, some community residents and businesses oppose replacing traditional intersections with alternative intersections like roundabouts or J-turns.
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New Smartphone App Uses GPS Technology to Warn Drivers of Lane Departures
Preventing vehicles from drifting out of traffic lanes is a top safety priority for transportation officials. An ongoing research project has produced a smartphone app that alerts drivers when their vehicles drift from a lane. The current phase of the project improved upon earlier versions of the app by adding GPS and significantly increasing the effectiveness of lane departure detection.
Crossroads 